Determination of the carbon diffusion coefficient for calculation of nonisothermal regimes of high temperature ions carbonitriding

The study on the factors, effecting the acceleration of the mass transfer of saturating elements - carbon and nitrogen - was accomplished on the 20KhN3MA steel. The saturation was performed at the experimental-production facility for the ion chemical-thermal treatment in a gaseous medium contain ing acetylene, ammonia and argon. After chemical thermocyclic treatment the samples were subjected to high tempering, after which the layer-by-layer chemical analysis was carried out. The mathematical processing of the experimental results was conducted by the steel saturation through carbon and nitrogen. The data obtained were used as the physical basis for developing the mathematical model. The equating for the carbon diffusion coefficient, used in the mathematical model of the ion cyanidation process, was obtained on the basis of theoretical assumption, accounting for the temperature effect by thermocycling on the elastic properties of the solid solution crystal lattice